<p class="lead">你发现了τ轻子！</p>

<section data-min-level="1">
  <h4>τ轻子</h4>
  <img class="img-responsive" src="assets/info/tau.png" alt="A plot from the original publication" align="right">
  <p>
    The τ (tau) is an elementary particle that can be thought of as a much heavier cousin of the electron, with a spin of &frac12;. It belongs to the family of leptons, along with the electron, the muon, and the three neutrinos. Despite the origin of the word lepton (meaning fine, small, thin) the τ is very massive at 1776.82 MeV/c<sup>2</sup>, which is nearly 3500 times the mass of the electron and around twice the mass of the proton.
  </p>
</section>

<section data-min-level="5">
  <h5>τ的发现</h5>
  <p>
    The τ was detected in a series of experiments between 1974 and 1977 by Martin Lewis Perl and his colleagues at the SLAC-LBL group. Their equipment consisted of SLAC’s then-new e<sup>+</sup>e<sup>&minus;</sup> colliding ring, called SPEAR, and the LBL magnetic detector. They could detect and distinguish between leptons, hadrons and photons.
  </p>
  <p>
    Martin Perl与Frederick Reines分享了1995年的诺贝尔物理学奖。 后者获得了中微子实验发现奖。
  </p>
</section>

<hr>
<h5><b>参考资料</b></h5>
<ul>
  <li><a href="http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.35.1489" target="_blank">The original publication by M. L. Perl et al.</a></li>
  <li><a href="http://en.wikipedia.org/wiki/Tau_(particle)" target="_blank">The τ lepton on Wikipedia.</a></li>
</ul>
